Finally pulled the head...

[wkilleffer]

Just out of curiosity, I checked my local yellow pages. There are a few auto oriented machine shops.

One is called Race Engine Design, and bills itself as the only complete machine shop in the area, and their add says they perform most if not all of the services which have been mentioned here as needed for my head. I'm not one who picks everything according to the yellow pages, but it is reassuring to know that there's someone local who *might* know what they're doing.

Now, I'm just hoping the head is salvageable and not cracked or warped.

 

[tony barnhill]

How far are you from Soddy Daisy?

I have a different opinion from the rest. Since you have the head off, have a machine shop go through it...evaluate/lap the valves, evaluate/replace or knurl the guides as needed, level the head. I would then just bolt it back on and see how things go.

You might be completely correct - however, since he didn't do a leakdown before pulling the head, there's no way to know exactly where the problem is...yanking the engine/trans is, at most, a 2 hour job....the engine can then be disassembled, checked, & reassembled in a Saturday & the car up & runnnig by Sunday.

Alot of this seems to involve dropping the pan and taking the pistons out.

Well, you could do it that way but its easier to yank the engine/trans...just rent an engine hoist for the weekend.

One small item I'll add: Make sure the lifters go back in their original positions. They mate themselves to the cam lobes, and should always go back in the same hole.

Ya got me ther, Jeff....I should've added that to the list....we could put together a pretty good 'engine refresh' checklist if we worked at it a bit!

 

[Hap Waldrop]

I vote for redoing the head first too, my money is on worn valve guides, don't waste your time knurling them, just get a new set (dirt cheap) and have them install, for now just go with iron guides, don't bother with bronze guides, tell them you want Chevy umbrella guide seals, don't bother with the MGB O ring seals. Oh I would go with the race machine shop, chances are they have a Sunnen or similar head machine, and they can put a nice three angle seat cut in there for you, tell them you want the seat area up the valve for street relaiblity, they will know what you mean.

 

[DrEntropy]

/bcforum/images/%%GRAEMLIN_URL%%/lol.gif /bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

Pressure test, three angle seats, renew guides (knurling won't stop oil from propagating down the stems on out-of- tolerance guides anyway), new seals and a Payen or FelPro head gasket.

And Bob's yer uncle!

 

[jlaird]

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif as well. Exactly what I would do. Might get away with under $100 if it is a good day.

 

[GB1]

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

 

[davester]

Wow, under $100? I think that here in California it would cost $100 just to get the machinist to touch the head, let alone do anything to it.

 

[tony barnhill]

i Agree - & I take lots of heads to my machine shop & even with my discount, I can't get one rebuilt for $100! Closer to $150-$200 I would think

 

[jlaird]

Hmm, used my provided guides, valves and springs and bits. He just did the work.

 

[tony barnhill]

That's possible

 

[jlaird]

I just for the small amount charged for stock head work to even think about messing with them. Not only that but to to a good job some good equipment is needed as well.

I know we use to grind valves by hand with a stick and a suction cup but those days are gone for ever at my house.

 

[Bugeye58]

Jack, I've got a seat cutter and a valve grinder, but still hand lap the valves the old fashioned way.
Works for me. /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
Jeff

 

[jlaird]

Guess that would be OK if it could be done in front of the TV, go right ahead and enjoy.

Think I will just wait till the shop calls and says "Your head is ready Jack."

 

[davester]

Oh, one more thing. Since the head is coming apart, now is the time to do a little performance-enhancement grinding on the combustion chamber and ports. Exact directions for this are in the performance tuning manual (that comes in the back of the Bentley manual I think), though I had mine done by Mike Goodman in LA (legendary MG only shop) and he had slightly different ideas. A little more money, but not that much in the grand scheme of things.

 

[DrEntropy]

See my post above and the link to the publications. CC'ing a head is aught but time and patience. Well worth BOTH, IMO. And hand lapping valve seats is still a thing done here at Chaos & Mayhem PTY., LTD.

Did the valves in a V-6 Ford (Mercury Cougar, actually) a while back and the silly thing ran just FINE after that.

A "high" sitting three-angle seat grind from the machine shop is even better.

 

[mikespain]

Happy and prosperous New Year to all. Hi Bill, if you look at the gasket,where the metal sealing ring is round each cylinder should be clean like in the top of the second foto,where you have a dark patch joining 2 cylinders is a sign that the gasket was not sealing properly,places where the ring is black ,across cylinders or outwards to a waterway or oilway is a definite blow .Which is what seems to have happened from the fotos,especially from fotos 5&6.Was the head torqued down properly and retorqued?Get the head checked,have it skimmed if needed to true it up,have the valves and guides checked for excess wear,valves and seats recut if necessary.Also clean the face of the block thoroughly andcheck it's flatness with a good straight edge,I would also consider changing the head studs.The head gasket would explain your overheating and your compression figures.

 

[Hap Waldrop]

I echo Jeff's comments on hand lapping seats in, I do alot of my seats on my budiies Sunnen machine nice three angle cutter that will cut everything in one quick swipe, but I still hand lap the seats in, anyone who does high quailty work will do so as well. I hate using a dobble stick (that the correct name for it), I bought a hand lapper that works in your power drill from Goodson Tool, love that thing. Especailly with a race motor when refreshing, but applies to some street heads as well depending ont their condition, hand lapping is alway a good first move, everytime you cut the seat and valve you are effectively wearing them out, and lowering your compression ratio, the whole idea is to remove no more material than needed.

 

[mikespain]

/bcforum/images/%%GRAEMLIN_URL%%/iagree.gif

 

[DrEntropy]

Funny, that. I have a drill attachment and one of those "click-clack" lapping tools (with a hand crank and a clockwise/counterclockwise stagger'd rotation) but seem to always go back to my dobblestick... but I guess if I were doin' as many heads as you, Hap, my palms would be tellin' me: "GET out th' DRILL, dummy!" /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Hap Waldrop]

Mine sounds a little different than yours, mine is called a Power Lapper made and sold by Goodson Tool, I love that tool. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif I also got a set of Neway seat cutters, which are a nice tools for DIYers, I use it some in the shop, but I mostly have it so I can do valve jobs at the track if needed.